The incredible change, his mother said, is owed to a technique called echolocation, similar to the method used by dolphins and bats, that allows Lucas to paint a picture of his surroundings using sound he creates himself.

He makes short, sharp clicking sounds with his tongue and mouth, and is able to translate the slight echoes that are returned into a spatial representation of a curb, a fence or a sofa - a technique called echolocation that he taught to himself.

In 1989, Pinker and a graduate student named Paul Bloom wrote a paper in which they argued that “language is no different from other complex abilities, such as echolocation or stereopsis,” and that “the only way to explain the origin of such abilities is through the theory of natural selection.”